Scriptures does not necessarily mean the vedas.There is no bar in teaching Ramayana, Mahabharata or the Smrities or Puranas which are also scriptures.
One reason of writing the Puranas is the very fact that "stri-sudra-dwijavandhunaam trayi na srutigochara" ie The Vedas can not be heard by the women, sudras and fallen tri-varnas.
So except Srutis, all are expected to be able to learn other scriptures.
Sri Sitaramdas Omkarnathji points out that these scriptures should be read under supervision of a guru (ie not to be read on own),as that is our tradition.(Ref: M-kar Baba, Sitaramdas Omkarnath, Mahamilan Math, page 2).
Without proper knowledge of Sanskrit and our tradition and culture, teaching or Learning of the above books are like teaching or learning English poetries and dramas without knowing english.
"Their true meanings can not be understood otherwise.(Ibid page 2).
So neither bad nor good effects will be the result.It will just be a wastage of time of all involved.
As Sitaramdas Omkarnathji points out:
Without proper tapasya, one can not understand the real meaning of the Sastras.(Omkarnath Rachanavali, Sitaramdas Omkarnath,Vol.7,page 1).Max Muller and Ramesh Dutta etc who have traslated the Vedas have seen only the skeleton of the Vedas and eaten the bones of the Vedas.(Ibid, page 97-8).